Automatic train-control system



J. N. PAUL AUTOMATIC TRAIN CONTROL SYSTEM Original Filed Nov.

20. 1519 2 Sheets-Sheet 1 J. N. PAUL AUTOMATIC TRAIN CONTROL SYSTEM Original Filed Nov. 20 1919 2 Sheets-$heet 2 A'TTOR NE Y.

Patented Aug. 5, 1924.

JOSEPH N. PAUL, OF ROCHESTER, NEW YORK, ASSIGNOR T0 GENERAL RAILWAY SIG- NAL COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

AUTOMATIC TRAIN-CONTROL SYSTEM.

Application filed November 20, 1919, Serial No. 339,399. Renewed January 2, 1923.

To all whom it may concern:

Be it known that I, JosEPH N. PAUL, a citizen of the United States, and resident of the city of Roc iester, in the county of Monroe and State of New York, have invented a new and useful Automatic Train- Control System, of which the'following is a specification.

This invention relates to automatic train control systems and more particularly to the means employed in such systems for transmitting controlling impulses or influences from the trackway to the moving locomotives, or other railway vehicles.

In some types of train control systems more particularly those in which the; control impulses are transmitted fromthe track to the vehicles inductively, that is, without physical contact, it is desirable, and sometimes essential for the safe and reliable operation of the system, that the engine element should be carried on the engine at the appropriate distance above the level of the track rails. In practice the wheels of locomotives and other railway vehicles gradually wear down in size, and having become Worn to a certain extent, are replaced by newwheels. Thus, the diameter of the wheels changes in use, and consequently the distance between the engine element supported by these wheels and the track rails will likewise vary, unless a corresponding-adjustment is made. Even if such adjustment is provided, however, it is not entirely safe to depend upon this adjustment being made when required, particularly when a new wheel is substituted for a worn wheel.

In view of these considerations, the primary object of my invention is to devise a train control system in which the proper adjustment of the car-carried element is automatically checked so that any improper adjustment will be immediately detected before the engine goes out on the road.

Other more limited objects and characteristic features of my invention will be in part obvious, and in part pointed out hereinafter during the description of the various embodiments I have devised for attaining this end; and the novel features ofmy invention will be pointed out in the appended claims.

In describing the invention in detail, I will refer to the accompanying drawing in which like reference characters refer to corresponding parts in the several views, and in which Figures 1 and 2 show diagrammatically the trackway and car equipment of an inductive system which I have selected to illustrate the adaptations and applications of my invention;

Fi 3 shows a mechanical arrangement for 0 ecking the adjustment of the engine element;

Figs. 4 and 5 show a modified arrangement in which an improper adjustment of the engine element is detected automatically when the engine starts out on a run; and

Fig. 6 illustrates a still further modification.

Referring first to the track equipment shown in Fig. 1, the track rails l of the railroad track are divided by insulated joints 2 into blocks in the usual way, one block I with the adjacent ends of two other blocks H and J being shown. The parts and circuits associated with the various blocks are the same, and for convenience will be given like reference characters with distinctive exponents. Each of the blocks is provided with a track battery 3 and a track relay 4, the same as in ordinary block signal systems. The usual train control system may be used With or without the usual fixed signals, depending upon the type of automatic control; and I have illustrated such fixed signals S conventionally without attempting to show their well known control circuits and devices. Associated with each block is a track element T which is adapted to influence by electromagnetic induction a cooperating engine element on a passing vehicle. In the particular construction illustrated, the track element T comprises a U-shaped magnetic core or yoke 5, with the usual pole pieces 6, and provided with coils 7 on its legs. (See Fig. 2.) In the arrangement shown, a trackway element T is located at the entrance to each block, a short distance in the rear of the insulating joints 2 (the normal direction of traffic being from left to right as indicated by the arrow); and the coil 7 of this trackway element is connected in series in a normally closed circuit including the front contact of a. line relay 8, the control circuit of which is taken through the front contacts of the track relays 4 of the corresponding block and the next block in advance. Thus, under clear trafiic conditions, the coils 7 of a trackway element T are included in a closed circuit of low resistance, and under dangerous traific conditions, when either the corresponding block or the next block in advance is occupied, these coils are open-circuited.

The engine element L comprises in general an inverted U-shaped magnetic core or yoke 9, provided with pole pieces 10, and having coils 11 and 12 on its legs. This yoke 9 is supported from the frame of the locomotive or other vehicle so that its pole pieces pass directly over the pole pieces 6 of the track element T. (See Fig. 2.) In connection with this engine element, I preferably employ an amplifying and detecting relay device of the thermionic or vacuum bulb type, commonly known as the audion. This device, being well known, has been illustrated conventionally, and comprises a filament F, a grid G and a plate P. One of the coils 11 on the yoke 9, which I conveniently term the field coil is connected in circuit with a battery A and filament F. The other coil 12, conveniently termed the receiving or secondary coil, is connected in the grid circuit of the audion which includes a battery C. A control relay R of any suitable type, preferably a quick-acting tractive relay with a large number of turns and a laminated core,

is connected in the plate circuit which include a battery B. The control relay R may govern any suitable form of train control apparatus or device; but since this apparatus forms no part of my present invention, I have illustrated such device K conventionally as an electro pneumatic valve, which may vent the train 'pipe and apply the brakes directly, or govern the operation of any other form of t-rain'control means. The train control device K is normally energized by a battery 13 when the control relay R is picked up, and is deenergized when said relay drops. In the construction illustrated, the dropping of the control relay R is only momentary, for the reason hereinafter explained, so that if continued operation of the device K is desired, it must be provided with a stick circuit or equivalent means, which, having no particular bearing upon the present invention, has not been illustrated.

The impulse transmitting means shown in Figs. 1 and 2 operates in accordance with the Well known principles of electromagnetic induction. The current normally flowing in the field coil 11 produces a magneto-motive force sending flux through-the yoke 9 of the engine element L and throu h the leakage paths around said yoke. This current also flows through the filament F and heats it to incandescence in the usual way, the voltage of'the. battery A and the number of turns and resistance of the field coil 11 being, of course, selected and proportioned to perform the functions desired. The battery C maintains a positive potential upon the grid G with respect to the negative end of the filament F, and the voltage of the battery B is selected so that normally (while the engine element L is not passing over a track element T) there is sufiicient current flowing in the plate circuit through the control relay R to keep its contacts closed and thereby maintain the control device K energized.

Under clear trafiic conditions, the coils 7 of the track element T being in closed circuit, when the engine element L passes over said track element T, the car equipment is not influenced sufficiently to cause operation of the control relay R. I attribute this result to the choking or bucking elfect of the closed-circuited coils 7 which, in accordance with well known principles, tend to prevent passage. of flux through the yoke 5, and thus prevent much change in the flux through the yoke 9. Under dangerous trafiic conditions, however, the coils 7 are opencircuited, so that the yoke 5 of the track element T presents in effect a dead magnetic loop to the yoke 9. Consequently, as the yoke 9 approaches and comes directly over the yoke 5, the reluctance of the magnetic circuit through the coils 11 and 12 is greatly reduced; and the flux through these coils, due to the magneto-motive force normally acting, is increased. Explaining this further, it is probable that a large part of the additional flux through the secondary coil 12.. is due tothe diversion of flux from leakage paths around the field coil 11 to the path through the yoke 9 and the secondary coil 12. This change of flux induces an E. M. F. in the coils 11 and 12, which tends to send current in a direction opposite to that in which current is then flowing. This opposing induced E. M. F. in the secondary coil 12 lowers the potential of the grid G and reduces the current in the plate circuit in a manner characteristic of the audion. Likewise, the induced E. M. F. in the coil 11 opposes the battery A and tends to reduce the current through the filament F, thereby partially cooling it, and likewise reducing the current in the plate circuit. Thus, the normal energizing current in the control relay R is so reduced as to cause its contacts to open. This opening of the contacts of the relay R occurs only during the passage of the engine element L over the track element T, and is, therefore, only momentary.

There are various other features and advantages of this type of impulse transmitting means, but since they have no direct bearing on the present invention and are discussed in another of my applications, I will not attempt to explain them in detail.

It will be evident that the operation of the control relay R in the manner just described is dependent upon the E. M. F. induced in the coils 11 and 12 of the engine element L. This induced E. M. F. in turn depends, among other things, upon the airgap between pole pieces of the engine element L and the track'element T. If the engine element is permanently attached to the engine, this airgap will become gradually shorter, due to the ,wearing down of the wheels. This is objectionable because the engine element may in time hang so low it will strike things along the track, and also because the airgap may become so short that the relay B may be improperly operated by the track rails at crossings, crossovers, or by other magnetic bodies along the track. If adjustment is provided for the engine element to take care of this condition, it may happen that the engine element will be some time or other accidentally or carelessly adjusted too high. This is particularly likely to happen when a new wheel of larger diameter is substituted for a worn wheel, since'the shopman may neglect to make a corresponding adjustment of the engine element. It is hardly likely that the engine element will be adjusted too low, because of the strict requirements of clearances, and even if such low adjustment should happen to be made, it will not result in an unsafe condition, and in the type of system shown and described, such low adjustment will immediately manifest itself by an operation of the control relay at acrossing or crossover; If it is desired to check against such a low adjustment, a gage block or bar, preferably yieldingly supported, may be located at the roundhouse or other appropriate place so that the engine element must pass over it, and suitable provisions may be made so as to detect if' the engine element strikes such block. In the case of a high adjustment of the engine element, however, due to 'a change of wheels or otherwise, the resultant airgap may be so long that the control relay R will not be operated when it should be, thereby rendering the system unsafe; and the principal purpose I have in mind is to provide a way of checking up and detecting such I an abnormal high adjust ment.

In connection with the foregoing discussion, it should be understood that the same principles apply to various types of impulse transmitting means other than that shown and described, andthat the unsafe condition produced by an abnormally high adjustment of the engine element is characteristic of several types of systems, including not only inductive systems, but systems employing physical contact, such as ramps and shoes. I desire to have it understood, therefore, that my invention is of general application and may be advantageously applied to various forms of impulse transmitting means. Further, I desire to have it understood that the impulse transmitting means shown and described to illustrate the nature and mode of operation of the present invention forms the subject of other applications and is not claimed herein.

Referring to Fig. 3, the housing for the engine element L carries a bracket or support 14 at each end which is connected by a wash-board adjustment to the inclined portion of a support 15 which is bolted to the frame 16 of the engine (in this instance the side frame of the pony truck). This inclined portion of the support 15 extends at an angle to the horizontal, for example, 45 as shown, so that as the engine element L is adjusted up and down, it is moved a corresponding distance lengthwise of the engine. Rigidly connected to the engine element L is a feeler or detecting arm 17, which extends horizontally in the plane of the wheel 18 to a point a short distance (for example, onehalf of an inch) from the tread of said wheel. With this arrangement, the engine element L'cannot be adjusted too high, regardless of the diameter of the car wheel, since the feeler arm 17 would strike the tread of the wheel before such adjustment could be obtained. Also, if the engine element has been gradually adjusted higher to correspond with the gradual wearing down of the wheels, and then it is intended to replace the worn wheel with a new wheel of larger diameter, the engine element must be correspondingly lowered, otherwise the feeler arm will interfere. Moreover, the position of the end of the feeler arm 17 with respect to the tread of the wheel provides a convenient way. of telling if the engine element is correctly adjusted.

In the modified arrangement shown in Figs. 4 and 5, a detecting track element 0, consisting of a U-shaped mass of iron, without coils, is located a short distance from the roundhouse, yard limits, or starting point of the engine (indicated at D). The car equipment shown in Fig. 2 is modified so that this track element 0 checks up adjustment of the engine element at the beginning of each run and automatically detects a high adjustment.

This modified car equipment shown in Fig. 5 includes the same normally energized field coil 11 (its energizing current in this arrangement being shown as derived from two sections of battery A and B -C) two separate audions U and .U, having their filaments F and F connected in multiple across the battery A; and two separate and oppositely wound secondary coils 20 and 21. The control relay R is connected to the plates P and P of the two audions in multiple, and is provided with front and back contacts 22 and 23, in addition to the front contact controlling the train control device K. The secondary coil 20 is connccted through the front contact 22 with positive battery and to the grid G of the audion U. The other secondary coil 21 is connected through the back contact 23 of the control relay R to negative battery and to the grid G of audion I. A cutout switch 25 of ordinary construction is included in the main battery leads for the purpose of cutting energy off of the circuits when the system is not in use.

This modified arrangement serves to detect a high adjustment of the engine element in the followingmanner. The switch 25 in practice will he opened by the engineer or hostler at the end of a run, and will be reclosed at the beginning of the next run. When the switch 25 is opened, current is taken off of all the circuits, including the energizing circuit for the control relay R. Thus, when the switch 25 is later closed at the beginning of the next run, the back contact 23 of the relay R will be closed, while the front contact 22 will be open. The had; contact 23 establishes the grid circuit for the audion U but the grid of this audion is connected to negative battery, so that no current flows in the plate circuit through the control relay R. The engineer must therefore proceed subject to the control of the train control device K until he passes the detecting track element 0. If the engine element L is not adjusted too high, the E. M. F. induced in the secondary coil 21, in the same manner as hereinbefore explained, reverses the potential of the grid G of the audion U and causes current to flow in the plate circuit of this audion and pickup the relay B. As soon as the relay R- is picked up, the closing -of its front contact 22 cuts in the grid circuit of the audion U which acts to maintain the control relay R energized. In this way, if the adjustment of the engine element is proper, the engineer will receive an automatic pickup at the detecting track element 0 and may proceed in the usual way; but if the adjustment is too high, such automatic pickup will not occur, and the engineer will then know that the adjustment is not correct.

The use of two secondary coils 20 and 21 and two audions U and U on the car does not interfere with the normal operation of the system at the regular track elements T. When the coils 7 of such track elements T are open-circuited, the E. M. F. induced in the secondary-coil 20 (the control relay R being up and the secondary coil 20 active) causes the control relay R to drop in the same manner as previously explained. The same change of flux in the yoke 9 which causes the dropping of relay R, acts upon the secondary coil 21 to make the potential of the grid G positive with respect to its filament, thereby picking up the control relay R. It should be understood that the action of the audions in this instance lags enough with respect to the dropaway time of the relay R topick it up after it drops. If desired, various expedients well known in the art may be employed to lengthen this lag and thus increase the reliability of the operation. It will be evident that the flux is increased to a maximum and then decreased to normal during the pasage of the yoke 9 over the yoke 5 of a track element T having its coils open-circuited. The relay R may drop during the approach of the engine element L to a track element T in the stopping condition, or as said engine element recedes, depending upon the winding and connections of the secondary coils 20 and 21; but in either case it is found in practice that the control relay R will momentarilydrop and then pick 11 If desired, detecting track elements 8 may be located at intervals along the track, so as to check up the adjustment of the engine element at various points in the run, as well as the beginning.

In the modification shown in Fig. 6, an arrangement of a pickup track element TI. and a stopping track element TS, located near the roundhouse or at the beginning of a portion of track equipped with track elements T, (indicated at D) is utilizedto check up the adjustment of the engine element L. The pickup track element TI, is constructed the same as the regular track elements T, but the coils 7 of this track element are connected to a normally deenergized stick relay 30. The stopping track element TS is constructed with an extra large core, or with its pole faces higher than the regular track elements T, or both, so that unless its coils 7 are in closed circuit, it will drop the control relay R on a passing engine, even though the engine element L thereon is adjusted as high as possible. The circuit for the coils 7 is controlled by a front contact 31 of the stick relay 30. and is closed when this stick relay is picked up. The relay 30 is provided with a stick circuit including a front contact 32 thereof, and a front contact 33 of the track relay 4 of the next block in advance. The purpose of this stick circuit is to maintain the relay energized until the engine has passed the stopping track element TS.

\Vhen an engine, equipped as shown in Fig. 2, leaves the roundhouse. or is about to enter signalled territory, it must pass over the pickup track element TP; and if the adjustment of the engine element L thereon is low enough, sutiicient current is induced in the coils 7 to pick up the relay 30. It will be noted that this action is due to the fact that the engine. element is in effect an electromagnet which induces a current in the coils 7 as it passes over them, the

strength of this current being dependent,

'th of the a-irgap. The coils 7 element TP being in a closed circuit, the

control relay R'is not dropped. If the adjustment of the engine element is proper, picking up of the relay 30 closes the circuit for the coils 7 of the track element TS, so that the train may pass without being stopped. If, however, the adjustment of the engine element is too high, the relay 30 will not be picked up, and the control relay R will be dropped as the engine passes the stopping track element TS, thereby manifesting this improper adjustment. When the relay 30 is picked up, it is stuck up until the engine passes the track element TS and enters the block I. Obviously, the relay 30 may be employed to clear a special normal danger signal, or control the operation of a switch or derail, instead of a stopping track element TS, the purpose being in each case to give a positive indication to the egineer as he starts out on a run of the fact that the engine element on his locomotive is not properly adjusted.

While I have shown and described different modifications of my invention, other adaptations and applications of the same principles and functions will be evident, and need not be disclosed in detail. Also, while I have explained the construction and operation of my invention as applied to one particular type of train control system, the same idea of means is applicable to any type of train control system including an engine element which should be carried at a proper distance above the level of the track rails. I desire to have it understood, therefore, that my invention is not limited to the particular features of construction shown and described.

What I claim as new and desire to obtain by Letters Patent of the United States, is:

1. In an automatic train control system, the combination with a vehicle, of an adjustable impulse device thereon, and means for determining the position of said device with respect to the track rails.

2. In an, automatic train control system, the combination. with a vehicle, of an adjustable impulse; device thereon, and automatic means for detecting when said device is adjusted an abnormal distance above the track rails.

3. In an automatic train control system, the combination with a vehicle, of an adjustable engine element thereon adapted to be influenced inductively by track elements through an intervening airgap, and means for automatically detecting when the engine element is adjust-ed too high.

4. In an automatic train control system of the type which employs an adjustable engine element adapted to cooperate with track elements, the combination with said engine element, of means for automatically detecting when it is adjusted at a greater distance above track rails than a predetermined maximum.

5. In an automatic train control system of the type which employs an adjustable engine element adapted to cooperate with track elements, ofautomatic detecting means responsive to an adjustment of the engine element above a predetermined maximum with respect to the track rails.

6. In an automatic train control system of the type which employs an adjustable engine element adapted to cooperate with track elements, of means effective near the starting point of a run for the vehicle for automatically indicating when the engine element is adjusted too high.

7. In an automatic train control system, the combination with a vehicle, of an impulse device carried thereby and vertically adjustable, and means movable horizontally as said device is raised and lowered and arranged to-cooperate with a wheel of the vehicle and prevent said device being adjusted too high with respect to the track rails;

8. In a train control system, the combination with a vertically adjustable impulse device carried on a vehicle, of means cooperating with a wheel of the vehicle for limiting the heighth above the track rails towhich said device may be adjusted.

9. In an automatic train control system an impulse device, on a vehicle adapted to cooperate with trackway means, means for adjustably supporting said device to permit it to be raised or lowered with respect to the track rails, said means causing horizontal movement of the device as it is raised and lowered, and safety means cooperating with the tread of a wheel for preventing adjustment of said device too high above the track rails.

10. In a train control system in which a vertically adjustable impulse element is carried on a Vehicle for cooperating with trackway means, means for checking the adjustment of said element comprising a gauging track element along the track, said means automatically manifesting on the car improper adjustment of the impulse element. 4

11. In a train control system in which a vertically adjustable impulse element is carried on a vehicle for cooperating with trackway means, the combination with apparatus on the car including a normally energized device controlled by said element and adapted to remain deenergized until restored, of means including said element and acting by exchange of flux between the car and the track for restoring said device when said element is properly adjusted.

12. In a train control system, an impulse element on the vehicle, a track device'normally in the stopping condition for cooperating with said element, and means partly on the track and partly on the vehicle and including said element for placing the track device in the non-stopping condition.

13. In an automatic train control system, the combination with a vehicle, train control apparatus on the vehicle, of an adjustable means carried by the vehicle and adapted to cooperate with suitable trackway means to control said apparatus in accordance with traflic conditions in advance, and means for determining the position of said device with respect to the trackway.

14. In an automatic train control system, the combination with a vehicle, train control apparatus on the vehicle, of an adjustable means carried by the vehicle and adapted to cooperate with suitable trackway means to control said apparatus in accordance with trafiic conditions in advance, and means for automatically detecting when the adjustable means is adjusted too high.

15. In an automatic train control system of the type which employs adjustable carcarried'means adapted to cooperate with traflic controlled trackway means, the combination with said car-carried means, of automatic detecting means responsive to an adjustment of the car-carried means above a predetermined maximum with respect to the track rails.

16. An automatic train control system and checking means therefor comprising, carcarried apparatus of the type in which the transmission of a control influence thereto causes a restriction in the movement of thetrain and includes an adjustable influence receiving device, trackway devices for transmitting such control influence under dan er traffic conditions and including a norma 1y active trackway device, and means automatically actuated upon the approach of a train to put said normally active device in its inactive condition only if the adjustment of said influence receiving device is proper.

17. In a train control system in which a vertically adjustable influence receiving element is carried on the vehicle for cooperating with trackway influence transmitting means, and means dependent on the position of the element for continuously indicating the adjusted position of said element with respect to the trackway.

18. In a train control system, the combination with a railway vehicle, of an influence receiving device fastened to said vehicle by wash-board type adjustable brackets, and means for determining when an improper adjustment of said device exists.

19. In an automatic train control system of the type in which control influences are transmitted inductively from the trackway to the vehicle, the combination of a normally energized brake control device on the vehicle which if momentarily deenergized will remain in its deenergized position until restored, a car element mounted for vertical adjustment and comprising a core of magnetic material rovided with an influence receiving coil a apted to receive control influences from the trackway, means for deenergizing said brake controldevice upon the reception of a control influence, trackway means including a normally active track element, and means for changing said normally active track element to its inactive condition if said car element is adjusted to the proper position and passes by said means.

201" In an automatic train control system ofthe type in which control influences are intermittently transmitted from the trackway to the vehicle at selected control points along the track, a car-carried impulse re ceiving element which is vertically adjustable on the car and which should not be more than a predetermined distance above the level of the track rails for proper operation of the system, of trackway means at the'point where the car starts out on its run and normally tending to restrict the movement of the car, and automatic means operated by said car element if adjusted low enough for rendering said trackway means inactlve.

JOSEPH N1 PAUL. 

